Drugs › Interleukin-5 receptor alpha-directed cytolytic antibody
Brand name · Benralizumab
Fasenra: adverse event reports filed with FDA
14,436 reports list it as a suspect or interacting product, 2012–2026. Class: Interleukin-5 receptor alpha-directed cytolytic antibody.
- 14,436
- reports as suspect product
- 0.1% of all reports · about 1,057 a year
- 1,492
- reports, 12 months to June 2026
- 2,473 in the 12 months before
- 56.4%
- marked serious by the reporter
- 65.3% across the class
- 9.6%
- record death among outcomes, as reported
- 1,386 reports · not verified by FDA
Between November 2012 and June 2026, 14,436 adverse event reports received by FDA list the brand name Fasenra (benralizumab) as a suspect or interacting product. Reports that mention it only as a concomitant medication (1,273) are left out of every figure here.
In the 12 months to June 2026, 1,492 reports listed it, down 40% from 2,473 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 1,057 reports a year and 0.1% of the 20,646,523 reports in the database, and 78.2% of the reports for the interleukin-5 receptor alpha-directed cytolytic antibody class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded asthma (14.9%), dyspnoea (9.2%) and drug ineffective (7.9%). A report can list several reactions, so shares add to more than 100%; 1,074 different terms appear across these reports. Asthma is recorded in 14.9% of these reports, about the same share as in the median interleukin-5 receptor alpha-directed cytolytic antibody drug (14.8%).
56.4% of the reports are marked serious by the reporter (65.3% across the class); 9.6% record death among the outcomes and 21.1% record hospitalisation, as reported. 45.9% of the reports came from consumers, and the largest patient age group is 45 to 64 (17%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Fasenra reports recording the termmedian drug in interleukin-5 receptor alpha-directed cytolytic antibody
- Asthmaasthma14.9%2,158
- Dyspnoeashortness of breath9.2%1,329
- Drug ineffectivethe medicine did not work as expected7.9%1,134
- Deaththe patient died; cause not stated by this term7.8%1,120
- Product dose omission issuea dose was missed5.1%738
- Headachehead pain5.1%736
- Coughcough4.4%629
- Pneumonialung infection3.6%519
- Fatiguetiredness3.2%468
- Pyrexiafever3%432
- Wheezingwheezing3%431
- Arthralgiajoint pain2.9%419
- Inappropriate schedule of product administrationthe product was taken at the wrong times2.9%416
- Rashskin rash2.9%413
- Device leakagethe device leaked2.8%403
- Malaisegeneral feeling of being unwell2.8%400
- Painpain, site not specified2.5%354
- Covid-19COVID-19 infection2.4%345
- Dizzinesslight-headedness or unsteadiness2.4%341
- Pruritusitching2.3%338
- Condition aggravatedthe condition being treated got worse2.2%315
- Injection site painpain where the injection was given2.2%315
- Hypersensitivityan allergic-type reaction2.2%311
- Urticariahives2.1%297
- Off label useused for a purpose or in a way not on the label1.8%257
- Chest discomfortchest discomfort1.8%255
- Nauseafeeling sick1.7%240
- Feeling abnormalfeeling odd or not right1.6%235
- Incorrect dose administered by devicethe device gave the wrong dose1.6%224
Top 30 of 1,074 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 2 drugs in the interleukin-5 receptor alpha-directed cytolytic antibody class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 18,460 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 70.5% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Asthma | 8,688 | 60.2% |
| Chronic obstructive pulmonary disease | 57 | 0.4% |
| Eosinophilic granulomatosis with polyangiitis | 53 | 0.4% |
| Eosinophil count increased | 42 | 0.3% |
| Hypereosinophilic syndrome | 14 | 0.1% |
| Dyspnoea | 12 | 0.1% |
The indication field is filled in by the reporter and is often blank; shares are of all 14,436 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Fasenra reports |
|---|---|---|
| Symbicort | 1,014 | 7% |
| Prednisone | 1,001 | 6.9% |
| Albuterol sulfate | 894 | 6.2% |
| Tiotropium bromide | 612 | 4.2% |
| Singulair | 574 | 4% |
| Montelukast | 539 | 3.7% |
| Albuterol | 505 | 3.5% |
| Advair Hfa | 292 | 2% |
| Spiriva Respimat | 281 | 1.9% |
| Breo Ellipta | 265 | 1.8% |
Other products listed in reports where Fasenra is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.
In context
| Measure | Fasenra | Interleukin-5 receptor alpha-directed cytolytic antibody | All reports |
|---|---|---|---|
| Reports as suspect product | 14,436 | 18,460 | 20,646,523 |
| Share of that pool | — | 78.2% | 0.1% |
| Reports, latest 12 months | 1,492 | — | 1,332,454 |
| Marked serious | 56.4% | 65.3% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 96 | 106 | 91 |
| Hospitalisation recorded, per 1,000 reports | 211 | 244 | 213 |
| Consumer-filed share | 45.9% | 51.6% | 45.8% |
| Top term, share of reports | Asthma 14.9% | median 14.8% | 0.5% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the interleukin-5 receptor alpha-directed cytolytic antibody class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Benralizumab | generic | 4,024 | 2,061 | 97.3% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Fasenra reports
How many adverse event reports has FDA received for Fasenra?
14,436 reports list Fasenra as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1,492 of them arrived in the latest 12 months. Another 1,273 list it only as a concomitant medication.
What reactions are recorded in Fasenra reports?
asthma (14.9%), dyspnoea (9.2%), drug ineffective (7.9%), death (7.8%) and product dose omission issue (5.1%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Fasenra was responsible.
How serious are the reports?
56.4% are marked serious by the reporter. Among the outcomes recorded, 9.6% of reports include death and 21.1% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
consumer or non-health professional (45.9%), physician (30.6%) and other health professional (15.1%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Fasenra rising?
1,492 reports in the 12 months to June 2026, down 40% from 2,473 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Fasenra was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Fasenra?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Fasenra as a suspect or interacting product; reports listing it only as a concomitant medication (1,273) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.